Two long-practised strengths of recent Octagon Artistic Director David Thacker (now Bolton University’s Professor of Theatre) have been the plays of Henrik Ibsen and Arthur Miller. So a Thacker production of an Ibsen play as adapted by Miller ought to have an unusual depth of understanding.

And it is a thrilling celebration of theatre as a crucible of clashing ideas. Every actor – several, familiar Octagon faces – gives what might be the performance of their careers. Every role slides smoothly into place, every voice makes its point in the disharmony that erupts among the Stockmann family and more widely in the small town that’s about to rake-in a fortune as a health spa when its medical officer discovers the health-bringing water is actually full of disease-bearing pollution.

Miller’s version emphasises that Dr Tomas Stockmann is back from austere years in Norway’s cold north, finally enjoying a comfortable home. When the gratitude he expects for preventing disease turns out to be anger from his brother, the mayor, followed by the local liberals - horrified by the cost of putting things right - reneging on their support, Stockmann’s public meeting is hijacked as the populace turn violently against him.

Barbara Drennan’s Katrine, his wife, is an independent-minded person trying to keep peace in the family with clear-minded, good-natured sense, while Peter Birrell, slick and politic as Mayor Peter Stockmann has a smooth-tongued plausibility. It’s easy to imagine Tomas provoking him when they were children and to understand how he developed the belief he is behaving rightly.

Among the venal liberals of the opposition press, John McArdle’s printer Aslaksen is outstanding. With his mane of grey hair he establishes the character’s insistence on moderation far more assertively than the whining also-ran Aslaksen often becomes. McArdle is credibly head of the property-owners’ association.

Comfortable domesticity is gradually stripped-away from James Cotterill’s set, while the multiple overhanging window frames remind that communities can be constricting as well as benevolent.